Silencing device for valve mechanism



Febo 113 LA Z SES? s. W. BRADBURN SILENCING DEVICE FOR VALVE MECHANISM Filed May 2, 1921 \3 7& 76 73 ZZ\\ Z2 20 I: Z0

JQQ/

Patented Feb. 13, 1923,

marten stares eater arce.

STANLEY W. BRAIDBURN, OF HAMMOND, INDIANA.

'SILENCING DEVICE FOR VALVE MECHANISM.

Application filed May 2, 1921.

T 0 all whom it may concern:

Be it known that I, STANLEY W. BRAD- BURN, a citizen of the United States, and a resident of Hammond, Lake County, and State of Indiana, have invented. certain new and useful Improvements in Silencing Devices'for Valve Mechanism, of whichthe following isdeclared to be a full, clear, and exact description.

This invention relates to silencing device for poppet valves of internal combustion engines, and its principal object is to eliminate the noise which is usually occasioned by the ordinary valve actuating mechanism of internal combustion engines' It is well understood by those skilled in this art, that a slight amount of lost motion is provided in some portion of the valve actuating mechanism for the purpose of enabling the valve to seat under the influence of its spring, and the noise or clicking sound is occasioned by the coming into contact of the two surfaces that are spaced'apart to obtain the lost motion. I have overcome this objectionable feature by providing a device which allows of lost motion in the valve actuating mechanism, but which has no spaced surface that come into contact, but, on the contrary,;all'

of the contacting surfaces constantly remain in contact. Another object is to pro vide a silencing device which positively eliminates the clicking sound, which may be employed in the form of valve mechanism commonly known as the overhead type. Another object is to provide a silencing device of simple, practical and substantial construction, wherein the parts are not liable to become rapidly worn or damaged.

lVith these and other objects and advantages in view. this invention consists in a silencing device for poppet valves of internal combustion engines, comprising a two part member for transferring motion from one reciprocating member to another, and having lost motion between its two parts, wherein contacting surfaces are constantly kept in contact with each other. The invention further consists in a silencing device of -.the character above set forth, in which a third or compensating member is employed for connecting togetherthe two parts of the two part member, said third member having a continuous surface contact with said two Serial No. 466,356.

parts, but permitting of lost motion therebetween. The invention further consists in the several novel features'hereinafter fully set forth and claimed.

The invention is clearly illustrated in the drawlng accompanying this specification in which: I

F1g. 1 is aside elevation of a silencing device embodylng one form of the present invention; Fig. 2 is aside elevation (partly broken out) but showing the parts in a different position; Fig. 3 is a vertical, crosssectlon taken on the line 3-3 of .Fig. 2; F 1g. 4 is a plan of a slightly modified form of the invention; Fig. 5 is a side elevation of said modified form; Fig. 6 is a view partly 1n side elevation and partly in central, vertical, longitudinal section of said modlfied form; and Fig. 7 is a view similar to Fig. 6 but showing the parts in a different position.

Referring to said drawing and first to F igs. 1 to 3, inclusive, the reference character 10 designates a primary actuating member, such as a push rod, and 11 designates'the valve stem of valve mechanism of the overhead type for internal combustion engines. As is well understood, the push rod 10 is reciprocated by a cam (not shown) to unseat theflvalve and a valve spring (not shown) is employed around the valve stem 10 to seat the valve when permitted to do so by the cam and interposed mechanism. In the ordinary practice, a rocker arm is provided between the push rod and valve stem for transferring motion from the push rod to the valve stem to unseat the valve and for transferring motion from the valve stem to the push rod when the valve spring acts to seat the valve. It is also well understood that in common practice, clearance is left between the rocker arm and valve stem to permit the valve to valve stem and is held in constant contact therewith. The rocker arm is rotatably mounted on a shaft or stud 16, which is mounted on the engine in any suitable manner. One arm 17 of the rocker arm member 14 is connected to the rocker member 13, so as to move therewith, and, as shown, said arm 17 may be forked at 18 to straddle the rocker arm member 13, and the two are connected together by the interposed compensating member 19, which is capable of rocking or rotating with respect to both rocker arm members 13, 14, and isso connected to said rocker arm members 13 and 14 as to permit of a limited amount of lost motion between the two, each time the rocker arm is actuated by the push rod 10 or valve stem 11, without, however, permitting any of the bearing surfaces to become separated,'but on the other hand keeping said surfaces in constant contact. Said compensating member 19 may be in the form of a crank or an eccentric, cam, or the like, and in the preferred form, it is illustrated as comprising a connecting pin rotatively mounted in the rocker arm member 13, and having two eccentrically disposed end portions 20, rotatively mounted in the forks 18 of the rocker arm member 14. For convenience in removing the parts, the bearing apertures in the forks are made large enough to permit the pin to be inserted through them, and sleeves 21 are placed in the bearing apertures in the forks and around the eccentric portions 20. I have illustrated cotter pins 22 secured in the eccentric portions 20 of the pin 19 for holding it in place, although it is to be observed that many equivalent arrangements may be substituted to hold the eccentric pin or crank position between the rocker arm members 13, 14. Between said rocker arm members 13, 14, is interposed a spring 23 which is here shown ,in the form of a coiled compression spring seated in recesses 24, 25, formed in the opposing sides of the rocker arm members 13. 14. aid spring is located and arranged between the eccentric pin 19 and stud or shaft'16, and tends constantly but yieldingly to hold the push rod in con.- stant contact with the cam.

Because of the eccentric connection between the rocker arm members 13, 14, a limited amount of lost motion is permitted between said two rocker arm members, thus enabling the valve to seat perfectly, but at allt-imes during the operation of the mechanism are all contacting surfaces kept in close contact. Fig. 1 shows the "parts in position assumed when the valve is seated and the low part of the cam has come into engagement with the push rod 10. In this position, the axes of the two parts of the eccentriopin 19 are substantially in a line running through the axis of the support for the rocker arm. When the high part of the cam first engages the push rod and com- 'mences to lift it, the initialupward movement of the push rod carries the eccentric pin up, causing it to travel in an arc of a circle around the axis of the eccentric portions 20, which are in the forks of the rocker arm member 14. When the axes of the eccentric pin come into vertical alignment (see Fig. 2), the eccentric portions 20 commence their lifting action on the forks of the rocker arm member 14, thereby depressing the end 15, and consequently depressing the valve stem 11 and unseating the valve; After the high side of the cam has passed the push rod, and the latter starts down toward the low side of the cam, the valve spring lifts the valve stem, swings the end 15 of the rocker arm member 14 upward and swings the forked end 18 downward, and when the valve has been seated'and the upward .movement of the rocker arm member end 15 ceases, the rocker arm member 13 continues to move downward under the influence of the spring 23, until such movement is arrested by the coming into engagement of the push rod with the low side of the cam. It is to be observed that the amount of lost motion may be and should ber limited to permit the eccentric pin to turn less than one'hundred, and eighty degrees before the push' rod reaches its lowermost position.

It will be observed therefore, that. although the push rod and valve stem may no move slightly with relation to each other, i and thereby move one of the rocker members with respect to the-other, the connections are always kept in contact, so that at no time is there any gap between any of the contactmg surfaces. It is understood that in the operation of an internal combustion engine of the type employed in automobiles or other motor vehicles or aeroplanes, the reciprocations of the push rod and valve stem are extremely rapid and in quick succession, and that the lost motion is taken up each time the parts are rec iprocated.

In the form illustrated in Figs. 4 to 7, inelusive, the two rocker arm members 13, 14, of the rocker arm are pivotally connected together, and'for convenience are pivotallv mounted upon the shaft or stud 16. Springs 26 are employed to swing or spread the two members 13, 14 apart. The push rod 10 amas? support, to obtain the necessarylost motion between the push rod 10 and valve stem 11. In this form of the invention, two rocking cam members 19 'are employed, which cam members are contained in recesses in the members 13, 14 and are mounted upon pins or studs 20 that are secured in said rocker arm members. Saidrocking cam members have curved surfaces 20? which are eccentrically disposed with respect to the axes of the pins 20 and said curved Surfaces of the rocking cam members 19 are constantly held in contact by springs 23* which are located in sockets formed in the opposite faces of the rocking members 13 14*. It is to be observed that when force is applied to either end of the rocker arm in an upward direction, the rocking cam members 19 will roll against each other upon their eccentric surfaces, until the minor axes of said eccentricsurfaces lie in astraight line, which position of the rocking cam members is illustrated in Fig. 6. When, however, the upward force is relieved on either end of' the rocker arm, the springs 26 then act to spread the two rocker arm members 13, 14K apart, while the springs 23 act to keep the eccentric faces of the rocking cam members 19 in rolling contact, as is clearly indicated in Fig. 7. It will thus be seen that, although the two rocker arm members 13, 14 of the rocker armare free to rock independently of each other so as to maintain constant contact with the push rod andvalve' stem, the

compensating element, namely the rocking cams, remain, in constant contact, so that when the rocker a-rm members are brought back to their initial position, all of the contacting; surfaces remain in contact, thereby eliminating any clicking sound which would otherwise occur in case any of the surfaces became separated from each other. I

More or less variation of the exact detailsof construction is possible without departing from the spirit'of this invention; I desire, therefore, not to limit myself to the exact form of the construction shown and described, but intend, in the following claims, to point out all of the invention disclosed herein.

I'claim as new and desire to secure by Let 'ters Patent:

1. A silencing device for poppet valves, comprising a primary actuating member. a valve actuatin member actuated by said primary actuating member, andbodily conne'cted thereto and having a limited amount of lost motion with respect thereto, anda rotative, compensating element, mounted in one of said'members and having a nonconcentric bearing face continuously contacting in the other.

2. A silencing device for poppet valves, comprising a primary actuating member, a valve actuating member actuated by said primary actuating member, and having a limited amount of lost motion with respect thereto, and a rotative, compensating element held in continuous contact in both of said members.

3. A silencing device for poppet valves, comprising a primary actuating member. a

valve actuating member actuated by said primary actuating member, and having a limited amount of lost motion with respect thereto, and a. rotative, eccentric'member having non-concentric bearing surfaces, one having its bearing in one of said members and'one having its bearing in the other of said members. i

- 4. A silencing device for poppet valves, comprising a primary actuating member, a valve actuating member actuated by said primary actuating member, and having a limited amount of lost motion with respect thereto, and a connecting pin, rotatively mounted in one of said members and having an eccentric portion rotatively mounted in the other of said members.

5. A silencing device for poppet valves, comprising a push rod, a valve stem, and a rocker arm member for transferring movement from one to the other, said rocker arm having an eccentric connection with said push rod whereby a limited amount of lost motion is had between said push rod and rocker arm member.

6. A silencing device for poppet valves,

comprising a push rod, a valvestem, a rocker armmember for transferring movement from one to the other and a compensating connecting element positively connected to said rocker arm and push rod which admits of a limited amount of lost motion between said push rod and rocker armmember.

7; A silencing device for poppet valves, comprising a push rod, a valve stem, a rocker arm member, fortransferring movement from one to the other, and an eccentric pin connection between said push rod and rocker arm member.

8. A silencing device for poppet valves, comprising a primary actuating member, a' valve actuating member actuated by said primary actuating member,-and having a limited amount of lost motion with respect thereto, and a rotative, spring pressed, compensating element, rotatably mounted in one of said members and having a non-concentric bearing'face rotatably mounted in the other member.

' 9. A silencing device for poppet valves, comprising a primary actuating member, a valve actuating member actuated by said primary actuating member, and having a limited amount of lost motion with respect thereto, and a rotative, spring pressed, compensating element rotatably secured in both of said members.

. 10. A silencing device for poppet valves, comprising a primary actuating member, a valve actuating member actuated by said primary actuating member, and having a limited amount of lost motion with respect thereto, and a rotative, spring pressed, eccentric member having non-concentric bearing surfaces, one Surface bearing in one of 'said members and the other surface bearing in the other of said members, whereby said primary actuating member and valve actuating member are positively connected together.

11. A silencing device for poppet valves,

comprising a primary actuating member, a valve actuating member actuated by said primary actuating member, and having a limited amount of lost motion with respect thereto,and a spring pressed connecting pin,

rotatively mounted in one of said members and having an eccentric portion rotatively mounted in they other of said members, whereby said primary actuating member and valve actuating member are positively connected together. I

12. A silencing device for poppet valves, comprising a push rod, a valve stem, and a rocker arm member for transferring movement from one to the other said rocker arm having a spring pressed eccentric lost motion connection positively connected with said push rod whereby a limited amount of lost motion is had between said push rod and rocker arm member.

13. A silencing device for poppet valves, comprising a push rod, a valve stem, a rocker arm member for transferring movement from one to the other and a spring pressed compensating connecting element be tween said rocker arm and push rod which admits of a limited amount of lost motion getween said push rod and rocker arm men- 14. A silencing device for poppet valves, comprisingv a push rod, a valve stem, a rocker arm member, for transferring movement from one to the other, and a spring pressed eccentric pin lostmotion connection between said push rod and rocker arm member.

STANLEY W. BRADBURN. 

